Journal of Applied Physiology, Vol 70, Issue 4 1743-1747, Copyright © 1991 by American Physiological Society
Endurance training increased HDL cholesteryl ester metabolism in rats
A. E. Pels 3rd, A. H. Terpstra and T. P. White
Division of Nutrition and Metabolism, Miriam Hospital, Brown University Program-In-Medicine, Providence, Rhode Island 02906.
We studied the effects of endurance training on the metabolism of
high-density lipoprotein (HDL, 1.063 less than density less than 1.15 kg/l)
cholesteryl ester and proteins in rats fed a cholesterol-rich (1%)
semipurified diet. The HDL were labeled with 131I in the apoproteins and
with cholesteryl-[1-14C]oleate in the esters. The HDL were intravenously
administered to endurance-trained (n = 10) and cage-sedentary (n = 10)
rats. Blood samples were taken over the next 36 h while the rats were
conscious and feeding. The trained rats had higher plasma HDL cholesterol
(0.72 vs. 0.28 mM) and HDL apoprotein (461 vs. 267 mg/l) concentrations
than the sedentary rats. The production or disposal rate of HDL cholesteryl
ester was higher in the trained rats (1.36 mumol/h) than in the sedentary
rats (0.72 mumol/h), whereas the production or disposal rate of HDL
apoproteins was similar in the trained (0.64 mg/h) and sedentary (0.60
mg/h) rats. The residence time of the HDL cholesteryl esters (4.72 +/- 0.22
vs. 3.37 +/- 0.21 h) and HDL apoprotein (7.65 +/- 0.36 vs. 4.55 +/- 0.28 h)
was longer for the trained than for the sedentary rats. These data indicate
that endurance training resulted in a significant change in the metabolism
of HDL cholesteryl esters and apoproteins as well as an increase in their
concentrations.
